Economic models for battery energy storage: improvements for existing methods

While the technology required to produce a viable battery energy storage system exists, the economic feasibility of building these systems requires justification. A generalized decision diagram was developed to ensure that all of the economic factors were considered and properly related for the customer side of the meter. Two economic models that had consistently given differing results were compared. One was the McKinney model developed at the University of Missouri at Rolla in 1987; the second was the SYSPLAN model developed by Battelle. Four specific cases were evaluated and compared. Differences were resolved on a point-by-point basis with reference to the current economic environment. The economic model was upgraded to include the best of both models based on the resolution of these differences. The upgrades were implemented as modifications to the original SYSPLAN (1986 version) to preserve user friendliness. The modified version is the result of an investigation into current standards and practices in engineering economics as well as power distribution engineering. Therefore, more accurate results are returned to the user. Comparisons have shown that this program generally returns values between the more conservative McKinney model and the more optimistic SYSPLAN model. However, the results do not follow a linear relationship between the two extremes.>